MODIFIED: Is it advisable to group two (or more) GPIO out pin to obtain more mA?

Started by flavigny, October 13, 2012, 07:33:20 AM

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flavigny

Hello,
I have to drive external load at 3V, 24 mA.
In the design, I will insert an Uln2803 driver.
BTW, is it possible to simply use more than one GPIO pin ?

I dream about this schema:
[modified to limit current on EACH pin.]
                   (diode)
    GPIOx------>|----(resistor 470 Ohms)----------+
                                                  |
    GPIOy------>|----(resistor 470 Ohms)----------+-(load)--Gnd
                                                  |
    GPIOz------>|----(resistor 470 Ohms)----------+

so, current from each pin is approximatively limited to 7mA.
                   

Does anyone could confirm ?
Regards.
PO.

Post-Scriptum: According to the answer below from Olimex, I read Chapter 37 and table 2.8 in: http://www.freescale.com/files/dsp/doc/ref_manual/IMX23RM.pdf . At this time I have not found the maximum power available.

olimex

generally yes, just look in the user manual or datasheet what is the max current which could be sourced from one port group.